Harrow-tooth.



No. 669,258. Patent 6d Mar. 5, I90l.

.1. LANZ.

'I-IABRDW TOOTH.

(Application filed June 8, 1900.)

(Nb Iodal.)

WITNESSES:

N TOFI Z TOFINEYS.

UNITED STATES PATENT Qrricn.

JOHN LANZ, OF PITTSBURG, PENNSYLVANIA.

HARROW-TOOTH.

SPECIFICATION forming part Of Letters Patent No. 669,258, dated March 5,1901.

Application filed June 8, 1900. Serial No. 19.559. (No model.)

To all whom it may concern.-

Beit known that I, JOHN LANZ, a resident of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in Harrow-Teeth; and I do hereby declare the following to bea full, clear, and exact description thereof.

My invention relates to an improved harrow-tooth; and its object is toprovide aharrow-tooth which can be made much more cheaply andexpeditiously than the present forms of barrow-teeth. The present formof common barrow-tooth comprises a bar rectangular in cross-section,with a forged point at one end and an upset enlargement or head at theopposite end. In making these harrow-teeth the bars are usually cut intosections and heated and one end thereof pointed in suitable dies and theopposite end upset to form the head. It has been proposed to form theseteeth by passing a hot bar through suitable die-rollers, which partiallysever the bar and form depressions in the sides thereof to give theblanks a chisel or wedge point. The blanks are then sheared off and thewedge-point is forged in suitable dies to form a pyramidal point and theopposite end is upset to form the head. Both of these processes,however, are slow and tedious and necessitate several operations withreheatings of the blanks and powerful forging machinery, thereby greatlyadding to the cost of the product.

The object of my invention is to avoid the defects in the old processesof forming harrow-teeth; and to this end it consists in taking a cold orheated bar, either rectangular or triangular in cross-section, shearingthe same on a diagonal line, so as to leave a pyramidal point, andshaping the opposite end to form a head, the process consisting,essentially, in

shearing and shaping the metal, no forging, strictly speaking, beingnecessary.

To enable others skilled in the art to make and practice my invention, Iwill describe the same more fully, referring to the accompanyingdrawings, in which Figure 1 is a perspective view of a triangular bar,showing by dotted lines how the same is out into the proper blanks. Fig.2 is a similar view of a rectangular bar. Fig. 3 is a perspective viewshowing diagrammatically the shearing-dies for cutting the bar. Figs. 4and 5 are vertical sectional views of the dies for centering the pointand forming the head of the barrow-tooth, the said figures showing thedies in different positions; and Fig. 6 is a perspective view of aharrowtooth formed from a triangular bar.

As shown in Fig. 1 of the drawings, I take a bar 1, triangular incross-section, and shear it on diagonal lines 2 2, thereby forming thepyramidal point 3 on one end of the blank and the flat or chisel point 4on the opposite end thereof, (which is the complement of the pyramidalpoint 3.) When the cross-section of the bar is a regular or nearlyregular triangle, the shearing is preferably done by means ofshearing-dies, such as illustrated in Fig. 3. The stationary or bottomdie 5 is provided with the horizontal ledge 6, on which rests the lowerflat side of the triangular bar 1, and with the face 7, said face beinginclined to fit the inclined side face of the triangular bar 1. Themovable die 8 is provided with a horizontal ledge 9, which is adapted topass under the lower flat side of the bar supported upon the horizontalledge 6 of the die 5, and is also provided with the face 10, which, asshown, is inclined in a manner similar to the face 7 of the die 5 to fitthe inclined side face of the triangular bar 1.- The die 8 moves in thedirection of the arrow indicated in Fig. 3, passing over the die 5, theconfiguration of the working faces of the dies being such that the baris held [irmly at all points while it is being sheared off. To furthersupport the bar while being sheared, suitable stationary supports (notshown) are provided, upon which rests the lower flat side of thetriangular bar. In the particular instance shown the ledges 6 and 9 areflat, as are also the inclined faces 7 and 10; but if the bar isrectangular or of irregular triangular cross-section instead ofequilaterally triangular the form of the ledges 6 and 9 and the faces 7and 10 will be modified accord ingly, andif abarof very flat triangularcrosssection is used ordinary shearing-dies can be employed. Fig. 2shows the manner of cutting a rectangular bar diagonally, so as to get apyramidal point 12, as distinguished from a chisel or wedge point. Itwill be observed that in shearing diagonally a bar either triangular orrectangular in cross-section it is formed into blanks having at leastone pyramidal point, while the opposite end is the complement of saidpoint and is either chisel shape or pyramidal.

After the bar is sheared in the manner above described the blank isplaced in the groove 13 of the die 14, said groove being V-shapedthroughout its length and of the same depth from the point 15 to thepoint 16, from which latter point it gradually diminishes in depth tothe end of the die, as at 17, where it vanishes. To facilitate themaking of the die 14, it is formed in two sections 18 and 19, thesection 19 having the V-groove of graduallydiminishing depth. Thesections 18 and 19, however, are firmly united together, so as to formsubstantially one solid die. They may, if desired, be made in a singlepiece. The die 14 is preferably circular and has a series of V-grooves13 cut in its outer surface and is mounted so as to have an intermittentrotary movement, so that a blank may be placed in one of the V-groovesand moved under the reciprocating die 20 and after being formed may bedischarged from the V-groove on the opposite side of the reciprocatingdie. On the outer side of the section 19 of the lower die is secured aplate 21, which forms, in effect, an end wall of said die. The movabledie 20 reciprocates in a vertical direction and has its lower faceformed fiat for the greater portion of its length, as at 22, and theouter end being downwardly inclined, as at 23. The die 20 isreciprocated by any convenient mechanism. (Not shown.) In front of thedie 20 is a reciprocating die 25, having its lower end shaped to formthe concave surface 26 and the convex surface 27, said surfaces runninginto each other. After the die 20 has pressed the blank into the groove13 and while it holds it firmly therein the die 25 moves downward andbends the end of the blank 1 down into the position shown in Fig. 4. Thedie 25 then recedes; but the die 20 still remains down, holding theblank firmly in the groove of the die 14. In this position theheading-die 28 moves in the direction of the arrow, Fig. 5, and itsconcave face 29 engages the end of the blank and curls it upward andinward to form the head 30, as shown in Fig. 5.

The operation of these dies is as follows: The blank is placed in one ofthe V-grooves of the die 14, and said die is then moved so that theblank is beneath the die 20, the blank being in the position shown indotted lines, Fig. 4. The dies 20 and 25 then move downward, the die 20pressing the blank down in the V-groove in the die 14:, bending it atthe point 31 and effectually centering the point of the barrow-tooth,and the die 25 bending the projecting end of the blank downward into theposition shown in Fig. 4. The die 25 then recedes and the heading-die 28moves forward, its concave face engaging the end of the blank, forcingsaid end upward and inward as shown. This operation forms a harrowtoothhaving a body triangular in cross-section, its point perfectly centeredwith reference to the body, its head neat in appearance, and is alsocentered. Furthermore, the curled-over head forms an eye on the end ofthe tooth, which serves as a means for stringing said tooth on a wire orother suitable means, so that a number of teeth can be readily attachedtogether in a convenient bundle for shipment or handling.

In some instances it may be desirable to bend the bar 1 before shearingthe same, and in that case if sheared diagonally at the point of bendthe point will be sufficiently centered, and no further centering isnecessary. If a bar rectangular in cross-section be used, it

willbe sheared upon diagonal lines, as indicated in Fig. 2, so as toform a blank having a pyramidal point at both ends, which is thereaftercentered to form the point of the harrowtooth, and the other end iscurled over to form the head. Such a blank, however, does not form abarrow-tooth that is perfectly symmetrical, and therefore I prefer touse a bar triangular in cross-section. If it is not desired to have thehead of the tooth centered with reference to the body, the blank may beforced endwise into a suitable die or matrix by an ordinaryreciprocating plunger or press, which will cause the point to becentered with reference to the body'and will curl over the other end toform the head.

It will thus be seen that my harrow-tooth can be made from triangular orrectangular bars by ordinary shearing and bending processes, and as norolling, reheating, and forging operations are necessary the teeth canbe made very rapidly and at but a slight cost above the price of thebars.

What I claim, and desire to secure by Letters Patent, is

1. A barrow-tooth comprising a body angular in cross-section having atone end a pyramidal point, and a bent-over portion at the opposite endto form a head.

2. A barrow-tooth comprising a body an gular in cross-section having atone end a pyramidal point which is triangular in crosssection and itsopposite end being provided with an eye. p

3. A barrow-tooth comprising a triangular body having a sharp point atone end and a curled-over portion at the opposite end forming a head andan eye at that end.

4:. A barrow-tooth comprising a triangular bodyhavinga sharp point atone end centered ramidal point, and a portion at the opposite [0 withrelation to the body and a curled-over end which is the complement ofthe point portion at the opposite end to form a head. formed into ahead.

5. A barrow-tooth comprising a triangular In testimony whereof I, thesaid JOHN LANZ, body having a sharp point at one end and a I havehereunto set my hand.

curled-over flattened portion at its opposite JOHN LANZi end to form ahead. Witnesses:

6. A barrow-tooth comprising a body an- F. W. WINTER,

gnlar in cross-section having at one end a py- ROBERT C. TOTTEN.

